Regulation of rotary compressors



W. GRUN.

REGULATION OF ROTARY COMPRESSORS.

APPLICATION FILED MAR.14, 1912. RENEWED NOV-12,1919.

1,372,502, Patented Mar.22,1921.

4 SHEETSSHEET I.

mvsuron MM 6 1w WITNESSES:

W. GRUN. REGULATION OF ROTARY COMPRESSORS.

APPLICATION FILED MAR. 14, I912. RENEWED NOV. 12.1919. 1,372,502. Patented Mar.22,1921.

4 SHEETS-SHEET 2.

. v I Z, I l

' a BY WITNESSES:

W. GRUN.

REGULATION OF ROTARY COMPRESSORS.

APPLICATION FILED MAR 14. I912- RENEWED Nov. 12.1919.

Ill]

Patented Mar. 22, 1921 4 SHEETS-SHEET 3.

I l H W. GHUN.

REGULATION OF ROTARY COMPBESSORS.

APPLICATION FILED MAR.14, 1912. RENEWED NOV. 12, 1919.

1,372,502, 7 I Patented Mar. 22, 1921.

4 SHEETS-SHEET 4.

WITNESSES: z-y" BY $4M g f M I ATTORNEY V INVENTOI? Ira-56615]! fm/ UNITED STATES PATENT OFFICE.

WILLIBALD anon, on FRANKFORT-ON-THE-MAIN, GERMANY.

REGULATION OF ROTARY GOMPRESSORS.

Specification of Letters I'atent.

Patented Mar. 22, 1921.

Application filed March 14, 1912, Serial No. 683,750. Renewed November 12, 1919. Serial 11'0. 337,622.

To all whom it may concern: Be it known that I, WILLIBALD GRUN, a citizen of the German Empire, and a resident of Frankfort-on-the-Main, Germany, have invented certain new and useful Imrovements in the Regulation of Rotary ompressors, of which the following is a specification.

It has been impossible hitherto to devise a satisfactory economical regulation of rotary compressors, without losses occuring through throttling in the suction conduit or the delivery conduit. Various methods have been proposed, but they have proved defective for reasons more fully set forth. hereinafter. The object of my present invention is to provide a regulator combining the advantages of devices previously employed, yet avoidingor neutralizing their defects. ith my improved regulator, the number of revolutions of the compressor is adjusted, within wide limits, automatically by the pressure or theamount of the air delivered by the compressor, yet at the same time, a speed regulator keeps the number of revolu tions as nearly constant as possible. Seemingly, these two results are incompatible with each other, but I secure them jointly by providing a speed regulator adjustable to different normal or regular speeds, but operating to keep the number of revolutions constant as long as the adjustment is not changed, a different normal number of revolutions corresponding to each particular adjustment; the adjustment of this speed regulator or governor is effected by the device which regulates the pressure or output of air, an increase in the number or revolutions of the compressor being accompanied by the setting of the speed governor for a hi her number of revolutions.

arious forms of my invention are illustrated by the accompanying drawings, in which- Figures 1, 1 2, 4r, 7 and 8 are diagrammatic views of'six different embodiments of my invention; Fig. 9 is a detail showing another form of regulator to be used in connection with my invention; and Figs. 3, 5 and 6 are pressure and output diagrams serving to explain the nature and advan tages of my invention. I

in most cases, as practised hltherto, the regulation of rotary compressors has been effected by means of a speed regulator (governor) tending to keep the number of been The operation of a revolutions of the mately constant.

governor is represented by the curve A-B compressor approxithe air pressure P and the abscissae the output or quantity of air Q, for the constant numbers of revolutions n, n n n, a, n". The curve A-B shows that any variation 1n the'output or delivery of air is accompanied by a material change in air pressure. Another drawback of this method is that it allows the capacity of the compressor to be varied only within restricted limits, and the output of air may therefore be reduced but slightly below the normal output, since otherwise the operation will become unsteady or jerky.

Another method of regulation which has proposed consists in. utilizing the staticor dynamic effects of the air, that is to say, in making the regulation dependent upon the pressure or the flow of air;-so that this mode of pressure or the flow of air respectively .approximately constant. this principle are combined with a governor (ball governor) of the well-known char acter, to preventany excessive rotary speed.

pressure regulating device ofthis type is represented by the line A-C of Fig. 3. This method, by varying the 'number of revolutions, keeps the air pressure almost constant, and allows the capacity of the compressor to be varied within considerably wider limits than according to the old method first referred to above, yet it is open to the serious objec- Devices working on The operation of this old regulation will keep the air tion that not only air pressure, but other factors as well will affect the number of revolutions, and this is particularly detrimental in the case of rotary compressors. Assuming, for instance, that the capacity of the compressor is adjusted by an air pressure governor, to the value corresponding to the point D on the curve 3 of Fig. 3,'and that then the drivin mechanism of the compressor fails suddenly, the regulation will not be affected, since at first the pressure in the compressed air piping (delivery pressure) will remain unchanged. In the event of a failure of the driving mechanism, the number of revolutions of the compressor will however fall at once say to a (curve 6) and of course with this reduced.

pressure in the distributing pipes, but will work ink a'jerky fashion, so that a regular operation will become impossible. This behavior is or" particular importance when the compressor is driven by means of turbines adapted tobe operated at one or the other of two pressures, say using livesteam in one case and exhaust steam in the other; the change from one mode of operation to the other tends to disturb the even running of the machine.

If on the other hand regulation is accomplished by means of a device governing the flow of air, which device is actuated 'by the flow of the air either directly or indirectly, as by the difi'erential'pressure effeet at two points of the stream of air,

.said device being connected either with the suction conduit o with the delivery conduit of the compressor, theregulating device will be adjusted according to variations in the amount of air passing through the suction conduit or the delivery conduit respectively. This adjusting operation corresponds either to'the vertical line fg of Fig. 6, or (and this is generally the; case) to a line inclined slightly in'the direction of the line h-i. That is to say, if the air pressure increases, the number of revolutions of the compressor is increased to such an extent as to keep the output constant or at least to allow but a slight diminution.

As stated above, it is the object of my invention-to combine the advantages of the .former methods of regulation while avoiding their defects.

The two embodiments of my invention.

I illustrated by Figs. 1 and 2 are adapted particularly for use in connection with compressors operated by an engine actuated by asingle medium (say, live steam). A ball governor 1 of the type customary in connection with steam engines has its sleeve 2 connected pivotally with a rod 2. At 3 this rod is connected pivotally with a link 29, pivoted at 27 to the endof a lever 9. At 28 the lever is connected pivotally with the rod 17' of the piston valves 17 and 18 which a i are connected rigidly and move in the distributing cylinder 8. The other end of the lever 9 is pivoted at 15 to the rod 14 of the piston 13 contained in the air pressure regulating cylinder 7 One face of the piston 13 is under the influence of the air pressure prevailing in the pressure piping or delivery conduit, the pipe 33 being in permaregulation purposes.

nent communication with said conduit; the other face of the piston 13 is engaged by a spring 16 opposing the action of said air pressure. The strength of the spring 16 determines the extent or range of variation in the air pressure which is allowed for At the right-hand end 4 the lever2'in the mechanism shown in Fig. 1 is pivotally connected with the rod 23 .number of revolutions approximately con- .stant, say within limits 0 to which is secured the piston 5 working in the cylinder 22 and also'the regulating element or regulating valve 6 arranged in the casing 24. This valve controls the passage of live-steam or other driving agent from the inlet 24' to the outlet 24", and the steam thus passing through the valve casing 24 then travels to the turbine or other engine which drives the compressor, that is to say, the valve 6 is interposed in the pipe supplying steam to the engine which operates the compressor.

A pipe 19 supplies a fluid under pressure (say, air or water) to the cylinder 8, be-. tween the. two pistons 17, 18. From the ends of the cylinder 8 pipes 20 and 21 lead to the corresponding ends of the cylinder I 22. The ends or heads of the cylinder 8 may be perforated to allow the air or other fluid to escape from one or the other cham- 8-- ber of cylinder 22 through'pipe 20 or 21, as the case may be, and the end chamber of cylinder 8 which at that time communicates with such pipe. The spindle 1 of the governor 1 is operatively connected with the compressor or with the engine driving the compressor. The sensitiveness of the governor 1 should be but slight (say from 10 to 20%), that is to say, it should respond only to variations exceeding a certain amount. In the construction illustrated by Fig. 1, the point 3 at which the lever 2 is connected with the link 29 and through it with the lever 9, is relatively close to the governor. spindle 1' and thus only a small portion, 10-11, of the regulating throw 10-12 will be required to bring the regulating element (valve 6) from one extreme position to the other.

The device shown in Fig. 1 operates as follows: V

If pressure rises in the pipe 33 connected with the delivery conduit of the compressor, the piston 13 will 'move upward, compressing the spring 16 and swinging the lever 9 and link 29 about the point?) as atem orary fulcrum. The upward movement 0 the lever 9 lifts piston valves 17, 18 from the closing position shown in Fig. 1, and thus allows fluid under pressure to pass from the pipe 19 to the pipe 20 and the upper end of the cylinder 22. The piston 5 is thereby caused to move downward and the valve 6 is brought toward its closed position, thus reducing the supply of steam to the engine, and consequently the output of the compressor with the number of its revolutions. In consequence thereof, the governor sleeve 2 will fall and bring the piston valves 17 18 back to the central position shown in Fig. 1. As long as the air pressure remains constant, the speed governor 1 will keep the I 1 or 2%. The air pressure governor or statlc pressure goveffect, since the ernor or regulator constituted by the piston 13' and the parts connected therewith will cause the governor sleeve 2 to shift between the points 10 and 12 and will thus adjust the number of revolutions within wide limits.

While the regulating device shown in Fig. 1 will work satisfactorily in many cases, it has the drawback that every variation in the driving medium (say steam) or in the operation of the engine actuating the compressor will cause a' considerable shifting of the regulating device and consequently variations in the output of the compressor. Under unfavorable conditions, these variations may even defeat entirely the intended considerable shifting movement may cause greater variations in the number of revolutions ofthe compressor lizfhan the speed governor has been calculated In order to overcome this drawback, I have devised the arrangement shown in Fig. 2. The speed governor 1, lever 2 andlink 29 are substantially the same as in Fig. 1, except that the lever 2 has a stationary fulcrum at 4 and that the connecting point 3 is approximately midway between the ends of the lever 2. The lower end of the link 29 is connected at 27 not only with the lever '9, but with a spring 26, secured at the other end to the rod 31 of a piston 30 movable in a cylinder 25 filled with oil or the like. This cylinder and piston form a dashpot, the two ends of the cylinder being connected by a pipe 32 in which an adjustable valve 32 is provided to vary the effective cross section of the passage connecting the two cylinder ends. The cylinder 25 is secured to the piston rod 23. The parts 5, e, 22, 24, 2e, 24", 20, 21, s, 17, 1s, 19, 17', 9, 27, 28, 15, 14, 16, 7, 13 and 33 are practically the same as in Fig. 1, but I have added a vertically adjustable ring 16 to vary the tension of the spring 16. It will be understood that the dash-pot and the spring 26 constitute a yielding or variable length connection between the link 29 and the piston rod 23, that is to say, become lengthened or shortened temporarily, but will resume its normal length when the disturbing influence ceases.

The device'shown in Fig. 2 will operate as follows: An increase of pressure in the delivery conduit of the compressor will, through the pipe 33, act to raise the piston 13 against the tension of the spring 16. The lever 9 is swung upward asin Fig. 1, rai ing the piston valves 17,718, and allowing fluid under pressure to pass from the ipe 19 to the pipe 20 and to the upper en of cylinder 22. This causes the piston 5 and valve 6 to be lowered, throttling the connec tion between 24: and 24". As described above, this reduces the rotary the connection may speed, causing thegovernor sleeve 2 to move downward, and restoring the piston valve 17, 18 to the closing or central position shown in the drawing. This movement ofthe piston 5 takes place very quickly, so that the oil cylinder 25 (rigidly connected with the piston 5) and its piston 30 will at such time move as if they were rigidly connected with each other, and will thus put the spring 26 under tension. Thereupon the spring 26 will gradually move the piston 30 upward in the cylinder 25, causing the oil to pass from the upper compartment of the cylinder through the pipe 32 to the lower compartment. The time required for this movement may be varied by adjusting the valve 32'. feet of throttling the passage of the valve casing 24; by the valve 6 will be to slow down the speed of the engine, which will in a comparatively short interval of time affect the fly-ball governor 1; at the same time, the spring 26, being under tension, will exert a force upon the pivot 3 which will tend to move the governor to the position which it will assume ultimately, viz: that corresponding to the reduced speed of the engine. Thus the spring 26 counteracts, at least in part, the slugglshness of the governor and causes it to respond more quickly to speed changes than it would otherwise. The dashpo-t arrangement 25, 30 enables the spring 26 to return to a neutral condition, that is, a condition in which it is neither under tension nor under compression, after it has performed the function described above. When the actuating fluid is admitted through pipes 19, 21 to the lower side of the piston 5, the operation of the spring and dash-pot will be the same as described above, except that the spring 26 would be placed under com pression and not under tension.

The spring 26 with the cylinder 25 and piston 30 also act as an isodromic connection or device, that is, as a device for bringing the governor 1 and the engine (after each regulating operation not produced by change of delivery pressure or flow) back to the original angular speed or number of revolutions as it existed before the regulating adjustment. This isodronlic regulating action, however, occurs only as long as the piston 13 (operated by air-pressure) is stationary, so that the pivot 15 as well as the point 4 will constitute (at least for the time being) stationary fulcrumsn In this case the movement of the governor sleeve 2 lengthwise of the spindle 1 will at first operate the parts positively, at the same time placing the spring 26 under strain (compression or tension), but the movement of valve 6 will be somewhat retarded because the movement of link 29 is partly expended in producing compression or expansion of the spring; this retarding is however compensated for as the spring gradually re- The efsumes its neutral condition. If for instance with the piston 13 at rest, the sleeve 2 of the governor 1 moves upward, the lever 9, swinging on the point- 15 as its -temporary fulcrum, will place the spring. 26 under tension and at the same time lift the piston valves 17, 18 so as to admit the medium' under pressure from the pipe 19 to the space of the cylinder 22 above the piston 5. This 25, but lags behind. At the same time, on

account of the reduction in the speed of the engine due to the throttling of the steam supply, the governor sleeve 2 will tend to slide downward on the spindle 1, the tension of the spring 26 assisting in thus returning Y the governor sleeve and also in bringing the lever 9 and piston valve 17 18 to the former position, in which said valves close the ports of both pipes 20 and 21. Thus, after the regulating element (the valve 6) has been adjusted so as toreduce the area ofthe steam passage, the governor sleeve 2 will have-the sameposition as before, so as to preserve and maintain the number of revolutions corresponding to the position of the air-pressure piston 13; The main purpose of the isodromic device (spring 26, cylinder 25, and piston 30) therefore is to maintain a constant engine speed as long as the air-pressure regulator (piston 13) remains stationary, even if the governor 1 should shift the valve 6 to a different position, say on account of a change in the steam pressure or in the vacuum.

Any variation in the power of the driving medium (say live steam) or in the power of the engine actuating the compressor, will cause a shifting of the governor sleeve 2 and therefore an operation of the distributing device located in the cylinder 8, to admit fluid under pressure either above the piston 5 or below said piston 5. The variable or isodromic connection between the speed governor 1 and the throttle valve 6 causes a new condition of equilibrium to be established in the event of any such disturbances in the engine (and not in the compressor), but the number or revolutions is not altered, that is to say, the governor sleeve 2 returns to its original position.

-The normal rotary speed is afiected only in the event of a change of air pressure in the delivery conduit of the compressor, since in this case only the piston 13 will be moved to bring the governor sleeve 2 to a new normal position, by means of the steps or oper ations described above;

The valve 6 of Figs. 1, 2, 7 and 8 (and the similar valves 43 and 49 of Fig. 4) are preferably hollow and double-acting, being arranged to throttle both the passage leading directly from the inlet 24 to the outlet 24, and the indirect passage leading from the inlet 24 through the interior of the valve and over the upper edge of the valve to the outlet 24". But it will be understood that other types of valves or re ulators may be employed.

n Fig. 4 have shown my improved regulating device (operating as a static pressure regulator, as in Figs. 1 and 2) in conjunction with the governors or regulators of a steam turbine adapted for operation at two different pressures. The regulating device proper is substantially the same as in Fig. 2, the exceptions being as follows: The dash-pot cylinder 25 is secured directly to the piston 5, within the cylinder 22, and instead of the connecting pipe 32 with valve 32, I employ a perforation or channel 32 in the piston 30 to connect the two ends or compartments of the cylinder 25.

The rod 23 projected downwardly from the piston 5 is not connected with the valve 6, as in Figs. 1 and 2, but is pivoted at 34 to a lever 35 fulcrurned at 36. At 87 the lever 35 is pivotally connected with a. rod 38, hollowed at its lower end to receive loosely the upper end of a rod 39 which.

connects the piston 40, movable in the cylinder 41, with the exhaust steam valve 43 contained in the-valve casing 44. The exhaust steam enters at 44 and passes out to the turbine at 44". A coiled spring 45 *tends to close the valve 43. The free end of the lever 35 has a pin or pivot 46' arranged to slide in the guide or loop 47 carried by the upper end of a rod 48 connected with the live steam valve 49. The casin 50 containing this valve is provided wlth an inlet 50 and with an outlet 50" through which the live steam passes to the turbine. A spring 51 tends to close the valve 49.

The upper part of the mechanism shown in Fig. 4, being almost identical with that represented in Fig. 2, will operate inthe same manner, so that detailed description will not be necessary. Its action on the steam-regulating valves 43 and 49 will be as follows: The valve 43 being hollow, the lower surface of the piston 40 is ermanently exposed to the pressure of tie exhaust steam in the valve casing 44; the upper surface of said piston is exposed to a constant pressure, as by connecting the uppercompartment of the cylinder 41, by means of a pipe 42 or othewise, with any space or chamber in which a (practically) constant pressure prevails, for instance the surrounding air. If the pressure of the exhaust steam is sufiicient to overcome the force of the spring 45, the exhaust steam valve 43 will be raised until its rod 39 en gages the end of the socket on the rod 38. A further upward movement of the valve 43 can therefore take place only when the point 34 of the regulating device moves, or in other words, the further movement of the valve 43 is governed by the regulating device.- If the point 34 rises until the pin 46 reaches the upper end of the guide 47 (and no farther), the exhaust steam valve 43 opens more and more, while the live steam valve 49 remains closed. If there should be a relatively considerable reduction of pressure in the delivery conduit with which the pipe 33 is connected, sufficient to raise the piston 5 and the lever 35 until the pin 46 engages the upper end of the guide 47 and lifts the same together with the live steam valve 49, then live steam also will be admitted to the turbine. If then thepressure of the exhaust steam falls below apredetermined limit (depending on the power of the spring the exhaust steam valve" 43 will close automatically, and the turbine will run exclusively on live steam, the reg ulatlngdevice in this case operating on the 'live steam valve 49, through the engagement of the pin 46 with the guide 47. Thus the pressure in the delivery conduit of the compressor Will be restored to the desired normalvalue, the number of revolutions not being aifected by the operation of the valves 43 and 49 just described.

Fig. 5 shows various positions of the lever 35 and connected parts when operated according to Fig. 4. In position G, the exhaust steam valve 43 and'the live steam valve 49 are closed (this is the same osition as shown in Fig. 4) in position the valve 43 is open, but valve 49 is still closed; in position J, both valves are open.

In Figs. 1, 2, and 4 I employ a regulator affected by the static pressure of the air to keep it as nearly constant as possible in other words,-a static pressure regulator. Instead of this, I may so construct the regulating device as to be affected by the flow of the air and to maintain a practically constant quantity or output of compressed air. The apparatus will be practically the same as described above, except that the connections with the delivery conduit and the means for receiving static pressure or kinetic energy from the fluid therein, will be such thatthe piston 13, or the rod 14, instead of being operated by a simple static pressure will be actuated by the direct or indirect action of the How or current of air. This may be obtained by the action of the current flowing through the suction conduit of the compres sor, or through the delivery conduit, the movement of the piston. 13 being say directly the compressor such as may result, for instance, from cooling. If for example, the stable condition C (Fig. 3) has been attained, and the air is cooled strongly, the air I pressure tends to rise, say to E. Since however the regulating device does not allow the pressure to rise, the apparatus will be adjusted to a condition represented by the point F, which indicates a higher output of air, at the same pressure as that obtaining at the point C, but at a higher rate of speed, being the same rate as would obtain at the point E (points E and F being both on the curve 3). If however the amount of air delivered is not the one corresponding to the point F, but only the smaller amount corresponding to the point C, the regulating devlce will reduce the number of revolutions to an extent corresponding to the increase in the output of the compressor due to the cooling ofthe air. Similarly, when employing the mode of regulation which tends to maintain a constant quantity or output of air, any increase in the cooling action will cause the pressure to increase or the number of revolutions to be reduced.

Generally, as constructed hitherto, systems or modes of regulation designed to keep the output constant, were based on the utilization of the kinetic energy in the suction conduit or in the delivery conduit of the compressor. The forms of my invention illustrated by Figs. 1 and 2 however are based on the fact recognized by me that a constant output against varying resistances may also be obtained by employing an air pressure regulator inconjunction with a speed governor, the air pressure operating to adjust the speed governor to the proper number of revolutions. The pressure governor should in this case be so constructed that an increase of air pressure will cause the compressor to rotate at a higher speed, and the regulating device should be so adjusted. (say in case of an intended regulation according to the line bm of Fig. 6) that the engine driving the compressor will make a revolutions per minute when the pressure regulator is in the position corresponding to the pressure at b, but it revolutions when the pressure regulator 'is in the position corresponding to the pressure at m).

'Such an arrangement is indicated in Fig. 1, where the connections of the pipes 20, 21,

with the respective chambers or compartments of the cylinder 22 are reversed as compared with the arrangement shown in Fig. l, but in all other respects the constructions are alike, so that the fragmentary showing in Fig. 1 will be suliicient.

In a similar manner, any particular regulation' desired, within the areas found respectively above the line c-b-e and below .the' line a bd, said areas being bounded in part by the lines a--bc and d-b-e ('Fig. 6), may be obtained by a proper adjustment of the pressure regulator and of the engine governor according to the air pressure. For instance, such regulation may be effected according/to the line 7c-Z. The shade lines in Fig. 6 indicate the lower boundary of the .area c-b-e and the upper-limit of the area iba respectively, and these shade lines have been added merely to better visualize the adjacent boundaries of said areas.

With. the hitherto known modes of regulating the output or quantity of air b means of a regulator operated by the kinetic energy of the air, regulation according to the line k-Z of Fig. 6 is not obtainable because with these old methods an increase of air pressure will occur only when the amountof air is diminished.

In a like manner, the use of a static pressure regulator was hitherto thought necessary when employing the mode of regulation which tends to keep the air pressure constant. However, just as regulation tending to keep the air output constant may be etfected bymeans depending on thestatic air pressure, so my invention also enables me to effect regulation tending to keep the air pressure constant, by means of a flow regulator, if this regulator is arranged to adjust the number of revolutions in a manner similar .to that described above with reference to the amount of air at the pointb; while, with lea the flow regulator in the position corresponding to the point 0, the engine governor s ouldf take-a position corresponding to the .-number of revolutions n.

Similarly, any desired regulation indicated on the compressor diagram may be obtained by a proper adjustment of the flow regulator and of the engine governor. However, the modes of. regulation lying within the area between the'vertical ordinate axis and the line L-b, above the curve n, and

within the area bounded by the two coordinate axes and the lines alb and b-7c are of special importance in view of the fact that difiiculties are experienced when attempting to carry out these modes of regulation by means of a static pressure regulator.

in compressed air plants employing any one of the regulations known hitherto, a decrease in the consumption of air will cause the air pressure to rise. The most advantageous regulation would be the one according to the line ;0g, in which the air pressure increases slightly with an increasing output, in about the same proportion as the pressure losses in the delivery piping to the place of consumption increase with an increase of the output or consumption. Regulation of the character indicated by the line pg has not been carried out hitherto, because this was impossible with the means available heretofore. The reason is that whenever the consumption of air decreases *as by throwing out of operation a number of tools operated by compressed air) the air pressure in the distributing pipes of a compressed air plant will rise necessarily. If I attempted to secure a regulation according to the line pq by means of a static air pressure regulator, for instance according to Figs. 1, 2 and 4, any decrease in the consumption of air would at once set the apparatus (that is, its governor) for a larger output of air, instead of a smaller output; the compressor would thus be adjusted at once to its greatest output or capacity, corresponding to the point r, and not to a reduced capacity, as it should be for a proper operation. My present invention however enables me to apply the above-mentioned advantageous mode of regulation to compressors, since the employment of a flow regulator will adjust the apparatus to a smaller number of revolutions and therefore to a lower air pressure, whenever the consumption of air decreases.

Figs. 7 and 8 illustrate two structures for carrying out this mode ofregulation, and Fig. 9 shows a detail of parts which may be substituted for certain portions of either of said twostructures. The arrangement shown in- Fig. 7 is very similar to that of Fig. l, differing therefrom practically only by having two pipes 33, 33 connected with the regulator. cylinder 7 at opposite ends, instead of the single pipe 33 of Fig. 1. The pipes 33, 33 are connected with the air conuit atpoints wheredifferent pressures prevail, the pipe33 being connected with the point of higher pressure. This may be done in the samemanner as in Fig. 8, where the pipes 33, 33' are'c'onnected with the air conduit 33 at difi'erent points of itslength, the air flowing in said conduit in the'direction indicated by the arrow, so that the pressure will be greater at the pipe 33 than at the pipe 33. referably the conduit 33" same manner 21S 15 is made with a contraction to increase the difference between the pressures prevailing in the pipes 33 and 33', the former being connected with the conduit at a place whereit still has its full width, and the pipe 33 at the narrowest point. The apparatus shown in Fig. 7 will work in substantially the same manner as the one shown in Fig. 1, with this exception that the regulator 7 of Fig. 1, having an air connection 33 only to one side of the piston 13, is a static air pressure regulator, while the regulator 7 of Fig. 7 (and that of F '8 likewise) having connections 33, 33 to lead air of different pressures to opposite sides of the piston 13, is a flow regulator. In one case therefore, the apparatus will respond to variations of air pressure, and in the other to variations in the current of air flowing through the conduit (such as 33").

The regulating device shown in Fig. 8 differs from that shown in Fig. 2 in the same manner as the device of Fig. 7 differs from that of Fig. 1. That is to say, the only material difference between Figs. 2 and 8 is that the former has a static air pressure regulator 7, with a single connection 33, while Fig. 8 shows a flow regulator 7, or a regulator responding to variations in the flow of air, since such regulator has two connections 33, 33 respectively which lead air of different ressures to opposite sides of the piston 13.

urther desorption of the apparatus shown in Fig, 8 and of its operation is therefore deemed unnecessary.

Instead of the regulator parts 7, 13, 16, 33, 33, 33", as shown in Figs. 7 and 8, I may employ the dynamic flow regulator represented in Fig. 9. Here the rod 14 is secured to a disk 13 which the kinetic energy, as sisted by the suction of the air flowing through the channel 33 of the conduit 33", tends to move against the pressure of the spring 16, thus operating the lever 9 in the done by the piston 13 in Figs. 7 and 8. Instead of the dynamic flow regulator described above with reference to Fig. 9, I may employ any othersuitable regulator constructed to respond, in any manner whatever, to the kinetlc energyin the air conduit.

In the examples shown in the drawing, the pston 13, or its equivalent, the disk 13 of ig. 9, is under the-influence of a spring (16 or 16") opposing In this case the adjustment or movement of the regulator rod 14 will be proportional to the pressure or flow. Thus, with the structures shown in Fi s. 7 and 8, regulation will be effected accor ing to any predetermined almost straight or uniforml curved line. If however instead of the uni ormly increasing resistance opposed to the s rmg 16 or 16", I provide means which will oppose an irregularly increasing resistance, I may obthe effect of air pressure.

tain a regulation following any other (irregular) curve desired. This may be done, for instance, by connecting the. compartment below the pipe such as 33, with a chamber in which a constant or a variable pressure prevails, (corresponding, for instance, to the connection of the pipe 33 in Fig. 1), such pressure acting on the piston 13 either'alone (in the event of using a variable pressure) or in conjunction with one or more springs. In this manner, I may modify theregulation from the curve 10-6-1" of Fig. 6 to the curve p bs, the two curves lying between the same numbers of revolutions or speed curves n and a, but the curve p-b s showing piston 13, by means of aa materially larger output of air at speeds hi her than n.

t is immaterial to the principle of my invention whether the regulation is carried out partly or entirely by mechanical appliances or by hand, and of course it is also immaterial what kind of engine is governed by the regulator. The particular regulating devices may be employed, as desired, in connection with electric motors, internal combustion engines, steam engines, such as a turbine plant adapted to be operated at two different pressures, etc. In the case of the lastnamed example, Fig. 4 shows the application of a static regulator to such plant; it will be obvious however, that this apparatus may be converted into a dynamic regulator, responding to variations in the flow of air, by adding connections corresponding to those marked 33, 33 in Fig. 8, or by substituting in connection with the operating rod 14, mechanism such as shown in Fig. 9. In the same manner as in Fig. 4, the supply of steam may be regulated in response to variations in the exhaust steam pressure, by a device operating independently of the air regulation. These and other modifications may be made without departing from the ,nature of my invention as set forth in the appended claims. It is immaterial of course, whether the apparatus compresses air or any other gaseous fluid.

I claim:

1. In a regulating device for rotary com pressors, the comblnation of a speed ovei-nor, a regulator responsive to variations in pressure conditions of the gaseous fluid, an element regulating the operation of the compressor, and operative connections from said element to the speed governor and to the said regulator, said connections including an isodromic member so that the operation of the compressor will vary only in response to variations in the pressure conditions of the gaseous fluid.

2. In a regulating device for rotary compressors driven by steam turbines adapted to be operated at different pressures, the combination of a speed governor, a regulator responsive to variations in the pressure conditions of the gaseous fluid, an element regulating the operation of the compressor by controlling the admission of steam, operative connections from said element to the speed governor and to the sand regulator, said connections including an sodromic device, a

. steam collector, and mechanism governed by pressure in saidcollector and connected with said regulating element to operate it independently of the action of said regulator and of said speed governor.

said element to the speed governor and to the said regulator, said connections including a cylinder connected with one of said parts, a piston connected with the other art,

a connection between the-chambers o the cylinder, on opposite sides of the piston, and aspiring tending to restore the normal relative position of piston and cfylinder.

4:. n a reg lating device or rotary compressors, the combination of aspeed governor, a regulator responsive to variations in Y the pressure conditions of the gaseous fluid, an element regulating the operation of the compressor, and operative connections from said element to the speed governor and to said regulator, said connections including a sprin and a dash-pot.

5. n a regulating device for rotary compressors, the combination of a speed governor, anelement regulating the action of the compressor, a connection between the governor and said element to normally keep the compressor running at a constantsspeed, a regulator responsive to variations in the pressureconditions of the gaseous fluid, a

valve deviceoperated by said regulator, means, controlled by said valve device, for moving saidelement, and a connection from said valve device to the governor and said element, to restore the valve device to its normal position, the connection of all of said i regulator;

arts being such that the governor will be adu'sted for a difierent normal speed substantially in response to a movement of said .6. In a device for rotary compressors, the combination of a speed overnor, a regulator responsive to variations in the pressure conditions of the gaseous fluid acted upon by the compressor, an element regulating the operation of the compressor, and operative connections from said element to the speed governor and to said regulator, the connection with the regulator being so constructed that an increase in fluid pressure will cause the compressor to rotate at a higher speed.

7. In a regulating device for rotary compressors, the combination of a speed governor, a regulator responsive to variations in the pressure conditions of the gaseous fluid acted upon by the compressor, an element regulating the operation of the compressor, and operative connections from said element to the speed governor and to said regulator, the connection with the regulator being so constructed that an increase in the fluid pressure will cause the compressor to rotate at a higher speed, and the regulator being arranged to maintain the flow of fluid per unit of time approximately constant.

8. In 'a regulating device for rotary compressors, the combination of a speed governor, a regulator for the quantity of gaseous fluid, responsive to variations in the flow of the gaseous fluid through a conduit, an element regulating the operation of the compressor, and operative connections from said element to the speed governor and to said regulator, the connection with the regulator being such as to cause the compressor to ro-' tate at a higher speed when the amount or": fluid increases.

9. In a regulating device for rotary compressors, the combination of a speed-governor, a regulator for the quantity of gaseous fluid, responsive to variations in the flow of the gaseous fluid through a conduit, an element regulating the operation of the compressor, and operative connections from said element to the speed governor and to said regulator, the connection with the regulator being such as to cause the compressor to rotate at a higher speed when the amount of fluid increases, and the regulator being arranged to keep the pressure from falling as the amount of fluid increases.

In testimony whereof I have signed this specification in the presence of two subscribing witnesses.

' WILLIBALD GRUN. Witnesses: I JEAN URUND, CARL'GRUND. 

